Method and apparatus j



Nov. 8, 1927. ,648,273

l F. J. HQFSCHNEIDERy METHOD AND APPARATUS FOR GRINDING TEETH Filed Jan. 5. 1924 l 4 Sheets-Sheet 1 INVENTO umfd L5 ATTORNEY Nov. 8, 1927.

- 1,648,273 F. J. HQFSCHNEIDER Y METHOD AND APPARATUS FOR'GRINDING TEETH Filed Jan. 5. 1924 4 Sheets-SheetZ IN VEN TOR.

Nov. 8, 1927. 1,648,273

F. J. HcFscHNElDER METHOD AND APPARATUS FOR GRIND-ING TEETH Filed Jam. 5. 1924 4 Sheets-Sheet 3 Nov. 8, 1927. 1,648,273

F. J. HOFSCHNEIDER METHOD AND APPARATUS FOR GRINDING TEETH Filed Jan. s. 1924 4 sheets-sheet 4 f s ATTORNEY Patented Nov. 8, 1927.

Unirse stares FREDERIC il". HGFSCHNEDER, OF RGCHESTER, NEW' YORK.

METHOD AND APLPA'RATUS FOR GRINDNG TEETH.

Application filed January 5, 1924.

My invention relates to a method and apparatus for grinding teeth, and has for its principal object to afford an almost painless system for grinding teeth or excavating cavities without necessitating injections into the gums to deaden nerves,

ll'lore particularly, the invention has or its purpose to provide 'tor bringing an anesthetic into immediate and direct contact with the portion ot' the tooth being treated, wit-hout affecting the gumv surrounding the tooth, and to afford mechanism tor carrying out such method in a practicable and ready inanner.

A further object ol my invention is to provide mechanism adapted 'for operation in conjunction with the conventional type of electrically operated dental engine, and to combine the parts in such a way as'to control automatically a supply ot' liquid to the hand piece, furnishing the liquid when the engine is running and cutting olf the supply when the engine stops.

An additional purpose of the improvement is to afford automatic instrrunentalities for maintaining the liquid at practically constant pressure and uniform temperature, and to accomplish the latter result by a heating unit that is thermostatically controlled either directly in conjunction with or independently ot the automatic liquid supply.

Still another purpose of the invention is to provide mechanism in which an electrical valve controlling device is either in the same circuit with the motor that driver the 'dental engine, or in an independent circuit and automatically controlled thereby, all the mechanism being equally adaptable to a stone tor surface grinding operations or to a. burr or drill lfor cavity excavations.

These and other objects and advantages oit the invention will appear clearly from the following description, when read in conjunction with the accompanying drawings, the novel y'features being pointed out in the claims following the description.

ln the; drawings:

Figure l is` a. vertical sectional view ot a portion of my invention in one embodiment;

'Figure 2 is a side elevation, with parts removed, and partially diagrammatic, showing a complete equipment incorporating the structure ot Figure l, the liquid supply tube being arranged for cooperation with a grinding stone;

Serial No. 684,564.

Figure 3 is a side View of the cabinet for housing the liquid tank and cooperating parts;

Figure l a. partial sectional view with parts in diagram, illustrating a modiiied arrangementofthe invention;

.Figure 5 is a partial sectional view illustrating another inodilication;

icated on the idea ot grinding a tooth and simultaneously applying an anesthetic-containing liquid at the point olthe tooth where grinding occurs, this being accomplished by feeding a continuous supply ot anesthetic-l containing liquid, pre'lerablv heated to a predetermined temperature, to the grinding tool, so that'it comes into Contact with the tooth and is pressed against the tooth by the grinding operation. Where I employ the term grinding througliout the following description and claims 'it 'is to be understood as comprehending either a stone or similar abrasive member such as employed llfor wort;- ing on outside surfaces, or a burr, drill or similar tool such as employed for excavating or drilling cavities.

I accomplish this result by jn'ovidingA a liquid supply tank which contains an anesthetic in solution, and from which liquid is led through suitable conducting means to al tube on the hand piece, and discharged at a point adjacent to the tool. The liquid is heated either in the gravity tank or some other point in the supply line and maintained at a predetermined temperature, while being automatically controlled so as to feed only when the engine is running and to be automatically cut oil when the engine is idle.

The invention isv susceptible o'l a number of different practical adaptations, several of which are herein disclosed, and l will first describe the arrangement illustrated generally in Figures 1 to 3. 1 designates a. suitable cabinet that may be mounted on a wall or other support and is provided with a door 2, serving' to house the liquid tanlr and electrical valve controlling` device. lili-thin the cabinet 1 is arranged a tanl 3 'trom which the liquid feeds to the supply line through an outlet pipe e', the liquid being maintained at a predetermined level in the tanlr 3 by means oit a valve 5 that is controlled by the float 6 and governs the inlet 7 to the tanlr. 'la is an overtlow from the tank 3. t

The liquid feces to the tank 3 automatically troni a. main reservoir 8, resting on the shelf 9, and provided with a suitable cover 10. rlhe cover 10 is readily accessible to the operator, and the usual practice is to lill the reservoir S at the beginning oi'f each day with al tres" supply ot liquid and the necessary quantity ot anesthetic in solution, to be determined by the operator. The liquid teeds from the reservoir 8 to the tanlr 3 through the pipe 11, the valve 5 and tloat 6 functioning to maintain a constant level in the tanlr 3, trom which the liquid feeds through the pipe Ll at a practically constant` pressure to the grinding tool.

ln order to control the supply ot liquid automatically, dependent upon starting and stopping` et the electric motor that drives the engine, l einploy an electrical device, preferably in the torn ot a solenoid 12,

`which is located in the cabinet 1, while 13 is a tube extending vertically through the solenoid to permit passage et liquid therethrough. 11i designates the core oit the solenoid carrying a valve 15, 16 being stop pins mounted on the valve and cooperating with a sloit 1T to guide and limit the movement ot the valve. lilllien the solenoid 12 is cnergized, the core 14; is littcd to open the valve and permit passage ot the fluid, and when the solenoid is cle-energized the core 's eleased and the valve falls, cutting ott1 the liquid supply. rlhe solenoid 12 is preterably in circuit that is independent oit the motor circuit, and whica may be controlled 'oy the this, l

motor switch. To accomplish e arranged the solenoid in a circuit which includes conductors 1S, 19 or 230 alternatively, d pending on whether the motor is operating in forward or reverse direction, conductor 21, and conductor 22 to the other side ot the, lin 23v designates a conventional type et `toot controller switch tor the dental engine motor, the motor and motor circuit not shown in Figure 2. but connected with .l ic toot controller switch Q3 as usual., is the movable switch member which is operatively connected with and moves the switch 25 that governs the solenoid circuit. W hen the switch 2Liis moved, see Figure 2, in one direction or the other, it closes the refiners solenoid circuit either through conductor 19 or conductor 20, depending on whether the motor is operated "forwardly or reversely, and thus the liquid supp is automatically governed by the operation of the motor, and is cut olli the instant the motor stops, or when the switch is in neutral position, as shown in Figure 22. 2G are hand .witches in the lines 19 and 2O to permit cutting out the liquid valve control on either the toi-ward or reverse operation ot the motoi and 27 is a hand switch tor entirely out the liquid valve control it deln order to heat the licuid, it is passed through a chamber 30 which contains a suitable electrical heating unit arranged in the circuit 31 between conductors 21 and 2Q, while designates thermostatic switch that opens the heating unit circuit when the temperature ot the liquid reaches predetermined point. The construction ot this heating unit will appear more clearly troni consideration ot Fi I re 1i, where it is embodied n connection with a inocilied form ot the .ntiorn which will now be described. in the arrangement shown in Figure 4L, the solenoid 35 is in the same circuit with the motor 3G which drives the dental engine and tool, while the heating element, designated generally at 37, is in an independent circuit that is controlled in the following manner. 3S designates a conductor leading i" oni the solenoid to the toot controller witch 39, and is a conductor leading "rem the solenoid to the motor. The heatunit 3'? is connected with conductor ll() leading from one side thereof, and conductor l1 leading trom the other side thereof through a switch l2 and conductor 13 to the other side et e line. The switch 112 is automatically controlled by the solenoid 35 through a secondary core Llei which operates imn'iediately following the main core that controls the valve lilith this arrangement, upon closing the n'iotor circuit, the core 4:5 is elevated and immediately thereaiter the core liti, which through the switch l2 closes the circuit to the heating elementl and thereby heating the liquid. Upon opening the motor circuit, the reverse operation talrcs place. ln order to prevent the liquid from becoming excessively het, l provide means tor maintaining it at predetermined teinpeature by means ot a ther-` mostatic switch l? located in oil in the chainber and forming part-ot the circuit to the heating element. llhen the liquid in the heating chamber reaches a predetermined temperature, tlie switch 4e? opens and breaks the circuit to the heating-unit.

ln the arrangement described and shown `l4`i"" 1m l0 tl lwel l in i. .gaies anc 4, ie errance va ve controlling device or solenoid .is in a circuit independent 'from the motor circuit, which rlatiai ter is controlled by the switch 24, and the l'ieating` unit is in the same independent circuit with the solenoid 12, Whereas in Figure 4 just described, the solenoid that controls the valve is included in the circuit With the motor, While the heating unit is arranged in an independent circuit, and automatically controlled from the solenoid.

Still another possible modilication is illustrated in Figure 5, in which the heating element 50 is arranged in the gravity tank 5l trom which theliquid is ted. lil/'ith this arrangen'ient7 the liquid heating element is entirely independent ot the valve controlling solenoid or ot the motor, and is operated from a circuit that includes on one side con-` ductor 52 leading tlnfough switch 53 to conductor 54, and on the other side conductor to the line. 56 designates a solenoid that controls the switch 53 and is in turn governed by a tlierrnostatic switch 57 in the tank Vllith the parts as illustrated, the circuit to heating element 50 is open. vlWhen the liquid is cooled suliiciently, switch r Will operate to close the circuit to solenoid 56, thereby closing switch 53 and energizing the heating clement to again bring the liquid to the predetermined temperature, after which the switch 57 again opens to cle-energize the heating element 50. lilith the arrangcn'ient last described, the liquid is always maintained at a certain temperature, independently oi the operation of the motor, aud is theretore always ready, whereas with the previously described arrangement, the heating element tunctions only when the motor is operating.

In Figures 2 and 6, l have illusrated ditlerent positions ot' the supply tube on Athey hand piece, when cooperating respectively with a stone or burr. 60 designates a tube toi-ming part ot the liquid supply means, and preferably detachably positionable on the hand piece (il, although it' desirable it may be pern'ianently located thereon, While 62 is an outlet portion or nozzle that is oliset from the main part ot the tube and is adjustable :trom the position shown in tull lines to that shown in dotted lines in Figure 2. rEhe full liue position shows the outlet portion adjusted tor cooperation with a small stone or abrasive 'element 63, While the dotted lines show it adjusted tor cooperation with a larger stone. Then used with a burr 64, see Figure 6, a slightly diililerent torni ot outlet or nozzle is employed, bringing the outer end at a point adjacent to the burr. In either case, the position ot the discliarge is such as to bring to the tool a. constant supply of liquid which forms thin film over the tool at all times, and is thus brought into intimate Contact with the tooth directly at the point undergoing treatment.

In some cases, it is desirable to provide a greater tlovv ot' liquid than in others, as for instance when using a drill, a greater volume or' liquid supply may be desirable than when using astone for sui-tace grinding, and in order to adapt the mechanism to such ditllerent uses l ein ilo a valve FO see Fioures 2 7 7 D and 8, that is adjustable' and provided With three ports 7l, 7 2 and 73 respectively, to permit the passage ot a coarse stream, tine. stream, or to drain the tube quickly when the main valve is closed. The valve is prei'- erably located in a housing 74 at a point adjacent to the hand piece 6l to permit ready control by the operator, and 75 is a port in housing T4, and cooperating with port 73 in the valve to permit quick draining ot the tube.

rl`l1e invention may be carried out in other ways thanby the particular' structures herein described, and this application is intended 'to cover any modilications or departures from the present` disclosure that may come vWithin the intent ot my improvements as herein set forth, or the scope of the tolloiving claims.

l claim: l

l. rlllhe combination with a dental engine hand piece, et a liquid supply tube positionable on the hand piece, a tank, a valve governing the flow ot' liquid in the tube, automatic means for opening` the valve when the engine is running and closing the valve when the engine is idle, gravity conducting means eadin 'from the tank to said tube, and automatic mechanism for maintaininga constant level of liquid in said tank in order to feed the liquid at substantiallv constant pressure.

2. lhe combination with a dental engine including a hand piece and an electric motor, ot' a liquid supply tube positionable on the hand piece, a motor switch, a valve controlling said liquid supply, an electrical device governing said valve, a circuit tor said electrical device, and a. switch in the last mentioned circuit operatively connected to and operated by the motor switch.

The combination with a dental engine, ot a liquid supply means comprising a tube on the hand piece ot the engine, means tor supplying liquid to said tube, and devices acting automatically to maintain said liquid at a predetermined temperature.

4. The combination with a dental engine including a hand piece and electric motor, of a liquid supply tube on the hand piece, a valve, automatic means for opening the valve When the motor is running and closing the valve When the motor is idle, and .devices acting automatically to maintain said liquid at a. predetermined temperature.

5. The combination With a dental engine including a hand piece and electric motor, of a motor switch, liquid conducting means, a valve controlling said liquid, an electrical device autoniatically governing said valve, a circuit tor said electrical device, a switch in fil) said circuit which is operatively connected to and operated by the motor switch, and means for automatically maintaining` said liquid at a predetermined temperature.

6. The combination with a dental engine including a hand piece and electric motor, a motor switch, liquid conducting means, a valve controlling said liquid, an electrical device automatically governing said valve, a circuit for said electrical device, and a switch in said circuit which is operatively connected to and operated by the motor switch, said circuit including` anclectrical device ior heating` the liquid.

7. The combination with a dental engine, of iiuid conducting` means, a valve governing the passage ol tluid through said conducting means, a motor switch, a circuit independent ot the motor circuit, and an electrical device in the last mentioned circuit for open ing` and closing said valve, a switch i'ior said independent circuit, the said motor switch controlling thev last mentioned switch so as to open the valve when the motor is running and close the valve when the motor is idle.

8. The combination with a dental engine, oit fluid conducting` means, mechanism `for feedingv a substantially constant supply ot liquid to the fluid conducting means by gravity, a valve governing,l the passage ot' fluid through said conducting` means, an electrical, device for opening and closing said valve, a circuit for said electrical device independent of the motor circuit, and a motor switch controllingl the last mentioned circuit so as to open the valve when lthe Inotor is running` and close the valve when the motor is idle.

Sl. 'if he combination with a dental engine, ot fluid conducting means, a storage tank trom which liquid is fed by gravity to said iluid conducting;l means, mechanism for maintaining a constant level ot liquid in said sto-rage tank, an electric motor, a valve governing' the pas-sage ot tiuid throueh said conducting means, a switch governing` said elec tric motor, and a. device controlled bysaid switch and operatinggautomat'fially to open ige/leere the valve when the motor is running` and to close the valve when the motor is idle.

l0. rilhe combination with a dental engine,

ot conducting` means, a storage tank iirom which liquid is ted by gravity to said fluid conducting' means, i'iieclianisni for iiiaintaining` a constant level of liquid in said storage tank, an electric motor :tor operating said engine, a motor circuit, a valve governing the passage of fluid through said conducting means, an electrical device for opening and closingv said valve, and an independent circuit ior vsaid electrical device, the motor switch controlling the last mentioned circuit so as to open the valve when the motor is running/'and close the valve when the motor is idle. t ll. The combination with a dental engine including' a hand piece and a motor switch, of a liquid supply tube for the hand piece, a valve 'controlling said liquid supply, an electrical device governing said valve, a circuit :tor said electrical device independent of the inotor circuit, and means controlled by the motor switch for controlling` the last men` tioned circuit automatically.

l2. The comhinationwith a dental engine .including a hand piece and grinding tool, an electric motor, a. liquid supply tube for the hand piece and grinding tool, a valve controlling,- said liquid supply, an electrica-l device governingsaid valve and acting automatically to open the valve when the motor is running,` and to close the valve when the motor is idle,'and a heatingl device acting automatically to maintain the liquid supply at a predetermined temperature before reaching` the grinding tool.

13. The combination with a dental engine, otfluid conducting means, a valve governing the passage of fluid through said conducting means, a motor switch, and means in the path ot' and moved by Said switch acting,` automatically to open the valve when the niotor is running` and to close the valve when the motor is idle.

ln witness whereof, l signed my naine.

FREDERC ,l l-llSCHNElDEl.

have hereunto 

